My heat doesnt always work too well in my truck it is the 4.2 litre engine.

It will sometimes show it heat up and others it wont. But if I stomp on the gas the heat will start to go up and it will work fine for a while.

I checked the radiator and the overflow is full to the line.

Any other ideas before I change the T-stat out? And do you recomend a certain T-stat?

 

You can try the t-stat first but I bet your radiator has a partial clog.Ive seen a few with your same problem turn out to be the radiator. Also,check your fan clutch.

 

How do I go about checking the radiator for a clog? I already replaced the tstat a few years back cause of this problem and now it returns again?

And on top of that it returned soon after and I just been putting it off awhile, cause now I am selling it and dont want to leave someone in the same spot when it gets cold out.

 

You're going to have to take it to a radiator shop.They can do a flow test on it.But,if you think its the t-stat by all means replace it first.

 

Will do the tstat this weekend .

Thanks guys!!